DavidR
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Posts posted by DavidR
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They use the same components as other AR speakers of that era and those capacitors are going bad - so its time. I recapped my 91s with film and my 10Pi and 90s using NPE but added a small film 'bypass' cap on all the series caps. I plan on doing my 9s using film but have NPE on hand if the sound doesn't sound as the speaker was designed to sound.
IIRC, A member here @lARrybody recapped 2 pairs of 9s; one with NPE and one with film. Hopefully he will give you his impressions of each.
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I'd leave the wiring alone. I don't think you'll hear any difference.
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@Ggutierrezm > They may have been 3a speakers but the tweeter and rear control panel has been modified/changed.
The woofers and mids look to be original AR parts.
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52 minutes ago, davidrmoran said:
you guys do know about the very active Allison speaker group online, yes?
allison-speakers@groups.io
all questions answered plus tips 'n' tricks
My anti-virus software stopped me from going there.
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Great link Frank. I will look into some that I see. Shipping will probably be a killer.
I found Larry's JBL stands on Music Direct. $330/pr. Look very nice and they'll work. $351 tax and shipping.
I'm also going to try my local fab shop I found. No shipping involved.
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Thanks Frank. Same stands as AR55 pointed out. They are a little beat up and kind of pricey for their condition.
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Thank you AR55.
Yeah, that's pricy.
I found a metal fabricator in my town but have not contacted them yet. Larry's stands look nice.
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Larry, Which AR speakers are those ?
My 10 Pi measure 14" wide, 10 13/16" deep
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Thanks for the updates
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Thank you.
Did they fill the tubing with sand or steel shot ?
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Here is a drawing for the AR90. Not sure if the AR9 has the (4) rolled up stuffing. My 1st pair of 9s appears to be just pieces shoved in and not the rolls. I have not ventured inside my 2nd pair of 9s too deeply.
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Yes, above the xover boards is stuffing. IIRC, it is 4 rolled up poly wadding. I have an AR drawing showing it. I will look for it after dinner and post it.
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The woofers and crossover area of the AR9 and AR90 is left empty on purpose (i.e. no poly-fill material). There is a thread on this site about it. The Tim Holl white paper on engineering the AR9 might also shed some light as to why. I believe it is an isobaric chamber.
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When in doubt always turn left.
Just be positive.
Good Luck in your search.
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Maybe
Eyes are open for AR5, AR3, AR3a and LST BUT only if I can get it for a decent price. Prices are crazy right now. Hoping to stumble on a pair at a yard sale with a seller who has 'no clue'. Same with a '58 to '60 Gibson Les Paul. 😉
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Thanks Gene. I was thinking along those lines.
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Hi Frank.
LSTs make me drool.
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1 hour ago, lARrybody said:
Teledyne purchased AR in 1967, the same year the AR3a was released. The AR3 was produced till at least 1970. The ADD line was probably around 1976 or 1977.
There were a lot of Advents being sold in those years. I would go with the AR3a. The AR2ax and AR4 earlier. The LST was not till 1970. All classic AR speakers.
I was thinking along those lines, too. But, there could have been several models in development at the time of sale. Are they AR or TAR?
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(1) What speaker is considered the last of the original Acoustic Research brand vs Teledyne Acoustic Research?
(2) AR3 or AR3a? Probably a personal preference but opinions wanted on the two speakers.
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Th thread Stimpy posted is the one I was thinking of.
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12 hours ago, johnfalc said:
Is the function of the switch the elimination of the series LC components often characterized as an "electronic automatic transmission" which raise the impedance on either side of the resonance peak of the woofers? Does it just disconnect the 2500uF/10MH part of the circuit, leaving the feed to the 470uF through the remaining 10MH inductor?
It eliminates the 2500uF cap in the woofer circuit that keeps the impedance from dipping below 3.2 ohms. It does not affect the LMR/UMR and tweeter impedance.
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On 7/16/2022 at 10:06 PM, lARrybody said:
They have a switch installed where I can run the woofers with a 2 ohm load. I will soon be trying this.
I believe they need to be bi-amped to accomplish this as the LMR/UMR and tweeter would still present a 4 ohm load. IIRC, Roy addressed this with a member (Valkyrie) and did not recommend it. If you do try it make sure your amp is stable in the 1 ohm range to handle the dip.
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Are talking about the wires or the connections on the drivers?
AR wiring should be that the darker color (e.g. blue) is neg and the lighter color (e.g. yellow)is pos (the example is for the tweeter wiring but the logic follows thru for each driver).
If you mean the drivers then there should be a sticker with the driver p/n applied near the spade connections with a red dot. The positive spade is closest to the red dot.
Anyone use tube preamp on AR9?
in Acoustic Research
Posted
I got rid of my Bob Latino ST120 tube amp after it arced 600vdc. Too close for comfort. I'm thinking it was a spider or cobweb on the pcb board; but that was enough. SS is easier. However, I still have my VTA SP12/PH14 Pre with some 'killer' NOS tubes and have used it with many speakers. I'm currently using it with a pair of MicroAcoustic FRMA-1 that I restored. Great match even with my 45wpc (80wpc 4ohm) A100 headphone amp.